Notes, abstracts, papers, exams and problems of Biology

Sort by
Subject
Level

Human Nutrition and Respiratory Systems: Functions

Classified in Biology

Written at on English with a size of 3.58 KB.

Human Nutrition

Human nutrition requires the coordinated function of the digestive, respiratory, circulatory, and excretory systems.

The Human Digestive System

The human digestive system involves the following processes:

  • Ingestion: Intake of food.
  • Digestion: Mechanical and chemical breakdown of food.
  • Absorption: Transfer of nutrients from the digestive tract into the blood or lymph.
  • Egestion: Elimination of substances that can't be absorbed.

Organs of the Digestive System

  • Mouth: The entrance to the digestive tract.
  • Pharynx: A muscular tube that connects the digestive system to the respiratory system.
  • Esophagus: A muscular tube around 25 cm long; it is normally closed but opens when food is ingested.
  • Stomach: Connected to the esophagus via a sphincter,
... Continue reading "Human Nutrition and Respiratory Systems: Functions" »
Karma: 6%
Visits: 0

A body is placed in a certain airstream

Classified in Biology

Written at on English with a size of 1.77 KB.

Non-s defences act against any type of microorganism. Is carried out by phagocytes: white blood cells that eliminate microorganisms. This process is phagocytosis./Inflammatory response is a non-s defence. When pathogens get through the external barriers, the blood cells  increase the blood flow. This help the transport of phagocytes towards the infected area. Inflammation occurs in the connective tissues with many blood capillaries. Large numbers of phagocytes destroy the pathogens. The remains are pus/Specific defences. When a non-specific response doesn’t stop a pathogen, there is: a specific immune response. Is carried out by lymphocytes, a type of white blood cells./Lymphocytes recognize antigens entering the body. The lymphocytes are
... Continue reading "A body is placed in a certain airstream" »
Karma: 6%
Visits: 0

JHH-7 doubling time

Classified in Biology

Written at on English with a size of 2.42 KB.

__________ 1. In sexual reproduction of fungi, spores are produce By mitosis.

__________ 2.Yeast is a rapidly growing, asexually reproducing Stage of some types of fungi.

__________ 3.Fungi form mutualistic symbiotic associations with Other organism.

__________ 4.Fungi play important ecological roles by decomposing Organic matter and by

breaking down and absorbing minerals From rocks and soil.

__________ 6.All fungi are helpful.

__________ 7.Plants are multicellular eukaryotes whose cells have cell membrane made of

cellulose.

__________ 8.Reproduction in seed plants is characterized by a Greatly reduced gametophyte

and a dominant sporophyte.

__________ 9. The flowers of many gymnosperms are adapted for Pollination by wind or by

animals.

__________ 10.Although... Continue reading "JHH-7 doubling time" »

Karma: 6%
Visits: 0

Human Biology: Immune System, Reproduction, and Cardiovascular Health

Classified in Biology

Written at on English with a size of 5.14 KB.

Vaccines and the Immune System

1. Vaccines introduce weakened or dead pathogens to stimulate the immune system. This prepares the body to fight future invasions by these microbes.

Vasectomy: Blocking Sperm Transport

2. In a vasectomy, the structure that is closed or blocked to prevent sperm from traveling from the testes to the urethra is the vas deferens.

Non-Specific Immune Responses

3. Sweat and skin secretions kill or limit the growth of many types of microbes. This control of microbes is an example of a non-specific immune response against infection.

The Amniotic Sac in Pregnancy

4. The fluid-filled structure in which the embryo is protected during pregnancy is called the amniotic sac.

Opportunistic Infections

5. Pathogens that cause opportunistic

... Continue reading "Human Biology: Immune System, Reproduction, and Cardiovascular Health" »

Karma: 6%
Visits: 0

Human Reproduction: Characteristics, Process, and Systems

Classified in Biology

Written at on English with a size of 7.74 KB.

Characteristics of Sexual Reproduction

Human reproduction is sexual. This means that it's necessary for two individuals of different sexes to take part.

  1. Each sex produces a different type of sex cell or gamete.
  2. Fertilization is internal; it takes place inside the female reproductive system.
  3. We are viviparous; the fetus grows in the mother's womb.
  4. We are sexually dimorphic. This means that males and females have physical differences. This happens in many species.

Process of Reproduction

  1. Gametogenesis: formation of the gametes.
  2. Fertilization: joining of the male and female gametes.
  3. Embryo Development: cell division and differentiation.
  4. Childbirth: birth of the baby.
  5. Development: cells increase and mature.

Changes in Adolescence

Adolescence begins with puberty,... Continue reading "Human Reproduction: Characteristics, Process, and Systems" »

Karma: 6%
Visits: 0

Aircraft systems

Classified in Biology

Written at on English with a size of 2.91 KB.

BCBBBACDCAADBADDCDDBAACCD

2a. Both fight pathogens
sep:attacks all kinds of pathogens
bio: attacks a specific type of pathogens
B. 
baso:makes chemicals that cause inflamation in bloodstream
macro:engulfs dead or damaged body cells & some bacteria
T: destroy body cells that are infected with pathogens
eos: injects poisonous packets into parasites such as protozea
neu: engulfs pathogens & foreign invaders; phagocytes
B:produce proteins that inactivate pathogens that have not yet infected a body cell
C.
WBC & certain organs - weaken pathogen cell membrane
B cells - destroy pathogens in one of 3 ways
body cells infected by a virus - stimulate an infected body cell to produce enzymes that will prevent viruses from entering & infecting them

3:
... Continue reading "Aircraft systems" »
Karma: 6%
Visits: 0

Cell Division, Chromosomes, and Cell Differentiation

Classified in Biology

Written at on English with a size of 4.34 KB.

Main Reasons Why Cell Divides

  • Larger cell demands more place for the DNA.
  • Larger cells result in less moving nutrients and waste materials across the cell membrane.

Information Overload

Cell grows, information is used to build the molecules needed for cell growth. DNA doesn't increase.

Exchanging Materials

Food, oxygen, water enter by the cell membrane, waste products also go out like that.

Division of the Cell

Forms 2 daughter cells. Cell division: process in which a cell divides into 2 daughter cells.

Asexual Reproduction

1 parent, cell divides by fission, little chances of genetic variation, found in bacteria, 2 offspring.

Sexual Reproduction

2 parents, cell divides by meiosis, genetic variation, found in mammals, 1 offspring.

Both

Forms of reproduction,... Continue reading "Cell Division, Chromosomes, and Cell Differentiation" »

Karma: 6%
Visits: 0

Galapagos Finches Evolution: Adaptation and Speciation

Classified in Biology

Written at on English with a size of 2.8 KB.

Galapagos Finches: Adaptation and Speciation

The Galapagos Finches originated from a single common ancestor. This initial population diversified, leading to various species adapting to different lifestyles. Adaptation, an evolutionary process, enhances a species' survival and reproductive success in a specific environment.

Environmental Influence on Finch Evolution

Environmental changes compelled the finches to adapt to varying diets, climates, and other factors. The finches' beaks were crucial in determining their diet. Initially, the finches utilized resource partitioning based on their beak sizes. Finches with smaller beaks consumed small seeds, while those with larger beaks ate larger seeds.

The Impact of Drought and El Niño

During a drought,

... Continue reading "Galapagos Finches Evolution: Adaptation and Speciation" »

Karma: 6%
Visits: 0

Endocrine System and Hormone Regulation: A Comprehensive Guide

Classified in Biology

Written at on English with a size of 2.51 KB.

Endocrine System

The endocrine system coordinates body processes using chemical messengers called hormones.

Functions of Hormones:

  • Control cell metabolism
  • Maintain the body's internal stability (homeostasis)
  • Regulate growth, sexual development, and reproduction

Endocrine Glands

Endocrine glands produce and release hormones, which the bloodstream distributes throughout the body to all cells.

Hormone Regulation

The endocrine glands and circulatory system work together to regulate hormones. For example, the pancreas secretes insulin when it detects excess glucose in the blood. Insulin causes muscle cells and liver cells to absorb glucose from the bloodstream.

Nervous System Coordination

The nervous system coordinates the activity of endocrine glands through... Continue reading "Endocrine System and Hormone Regulation: A Comprehensive Guide" »

Karma: 6%
Visits: 0

The Endocrine and Nervous Systems: A Comprehensive Overview

Classified in Biology

Written at on English with a size of 2.98 KB.

The Endocrine System

Hypothalamus: Produces releasing hormones, which control the activity of the pituitary gland.

Pineal Gland: Controls the daily sleep-wake cycle and produces melatonin.

Pituitary Gland: Directs the activity of other endocrine glands with a variety of hormones.

  • Gonadotropic Hormones: Act on the sex organs.
  • Oxytocin: Stimulates uterine contractions during childbirth.
  • Growth Hormones: Control the elongation of bones.

Thyroid Gland: Regulates the body's overall metabolism with thyroxine. Produces calcitonin, which increases blood calcium levels.

Adrenal Glands: Regulate metabolism with cortisol, regulate kidney function with aldosterone, and prepare the organism for high-stress situations with adrenaline.

Pancreatic Islets: Control blood... Continue reading "The Endocrine and Nervous Systems: A Comprehensive Overview" »

Karma: 6%
Visits: 0