Notes, summaries, assignments, exams, and problems for Biology

1. Who Discovered the Genetic Material?

Frederick Griffith

2. When Was the Genetic Material Discovered?

1928

3. What Did Frederick Griffith Do With His Major Experiment?

He studied two strains of the bacteria Streptococcus pneumoniae which causes pneumonia. He found that one strain could be transformed, or changed into the other form.

4. What Did Avery and Colleagues Identify?

They identified the molecule that transformed the R strain of bacteria into the S strain.

5. What Did Hershey and Chase Publish in 1952?

They published results of experiments that provided definitive evidence that DNA was the transforming factor.

6. How Does a Virus Replicate?

Viruses cannot replicate themselves; they must inject their genetic material into a living cell to reproduce.... Continue reading "The Structure and Function of DNA: A Comprehensive Guide" »

Understanding the Heart's Anatomy

The heart is the pump which circulates the blood throughout the body. It is approximately the size of a person's fist and is located in the chest, slightly left of center.

Myocardium: The Heart's Muscular Walls

The myocardium refers to the muscular walls that make up the heart, essential for its pumping action.

The Heartbeat and Cardiac Cycle

The heartbeat refers to the rhythmic sounds that the heart makes as it pumps blood. This rhythm can also be observed by feeling the arterial pulse. The left and right halves of the heart function as synchronized pumps, working simultaneously.

Phases of the Cardiac Cycle

The cardiac cycle describes the sequence of events that occurs during one complete heartbeat. It consists of... Continue reading "The Human Heart: Anatomy, Function, and Blood Circulation" »

blood circulation: closed: blood always circulates through the blood vessels and never leaves them. double: blood must flow through the heart twice to complete a circuit. oxygenated and deoxygenated blood never mix. they circulate through different circuits. systematic and pulmonary circuits: VI>CU>AD> VD> PUL>AI

Adaptation of Xylem to its Function

• Long, made from cells joined end to end to form tubes/vessels
• Cell walls thickened with lignin, a hard, strong material
• Lignin makes cell walls waterproof
• Cells have no cytoplasm or organelles (no cell contents)
• No end-to-end walls between cells
• Pits in the walls for water movement between vessels

Define Transpiration

Loss of water vapor from plant leaves by evaporation of water at the surfaces of the mesophyll cells followed by diffusion of water vapor through the stomata.

Leaves have many more stomata in their lower epidermis than they do in their upper epidermis, and most transpiration happens there.

Factors Affecting Transpiration

• The large internal surface area provided by the interconnecting air spaces between

Asexual Reproduction in Plants

Asexual reproduction is the process through which an organism produces other organisms without the participation of more than one parent.

Methods of Asexual Reproduction

Runner or Stolon

Runners or stolons can produce buds that develop into new plants that are clones.

Fragmentation

Fragmentation occurs when a small part of the plant falls off onto the soil and begins to grow into a new plant.

Budding

Each bud will grow like a clone of the original plant that produced it, such as a potato.

Gemmation

Gemmae are shed and dispersed to other areas, where they grow to produce new individuals.

Vegetative Propagation

Vegetative propagation happens when someone takes a part of the plant and replants it in another place.

Animal Tissues

Types

Recognize the following words and give Pinyin for them:

• 住院 zhùyuàn
• 学期 xuéqī
• 专业 zhuānyè
• 基础 jīchǔ
• 时间 shíjiān
• 要求 yāoqiú

Make up sentences with the given words:

• 这学期你们开了几门课？我想去医院看朋友。
• 窗户上挂着一个牌子。在病历里夹着吗？什么时候可以出院？
• 我昨天晚上一点才睡觉。学校下个星期六开运动会。我们留学生可以参加吗？

Choose the proper words to fill in the blanks:

• 你的解剖实验报告写完了吗？
• 星期一我已经把请假条交给老师了。
• 还是不能确定是肺癌还是肺结核。
• 这是一部关于中国历史的电影。
• 上星期卡瓦不是来借过你的词典吗？

Common rescue drugs for allergic shock:

• Immediately subcutaneous

Central Nervous System

Cerebrum

The cerebrum interprets information sent by sensory receptors, regulates muscle activity, and is involved in emotional and intellectual processes. It has two hemispheres joined by the corpus callosum, which is made up of neuron axons. The cerebrum also has a superficial layer of gray matter called the cerebral cortex.

Thalamus and Hypothalamus

The thalamus and hypothalamus produce hormones and control the endocrine system.

Cerebellum

The cerebellum controls motor coordination, posture, and balance. It has two hemispheres and a central zone.

Brainstem

The brainstem connects the brain to the spinal cord. It includes the medulla oblongata, which regulates blood pressure, heartbeat, and respiration.

Hemispheric Specialization

There... Continue reading "Human Nervous System: Structure, Function, and Disorders" »

What are we made of?

Carbohydrates, Fats, Proteins, Water.

Metabolism:

All chemical reactions that take place inside the body.

Carbohydrates:

Include sugars and starches. Contain three types of atoms: carbon, hydrogen, oxygen.

Sugars: The simplest kind of carbohydrates are the simple sugars or monosaccharides, such as glucose and fructose. If two monosaccharides join, a disaccharide is formed.

Polysaccharides:
If many simple sugars join together, a molecule called a polysaccharide is made. (Starch and glycogen are polysaccharides.)

Carbohydrates Functions:
Energy: Energy is released by respiration. The carbohydrate used in respiration is usually glucose.
Transport: Animals transport glucose around the body, plants transport sucrose.
Storage: Plants store... Continue reading "Understanding Carbohydrates, Fats, Proteins, and Enzymes" »

Darwinism

Charles Darwin (1809-1882) and Alfred Russel Wallace (1823-1913)

Basic Principles of Darwinism

1. Individuals within a population have anatomical, physiological, and behavioral differences.
2. Each species produces more offspring than can survive to reproductive age, leading to competition.
3. Competition for resources (struggle for existence) explains why many offspring die.
4. Natural selection favors individuals with advantageous variations.
5. Surviving individuals pass favorable variations to their offspring.

Survival of the Fittest

Individuals with favorable characteristics survive and become more common, potentially leading to new species over generations.

Example: Giraffes

1. Giraffes initially had varied neck and leg lengths.
2. Natural selection favored