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

Unit 8. Endocrine System

The endocrine system is made up of the endocrine glands and the hormones they produce. Those glands produce hormones, chemical messengers that affect many cell processes (accelerating, delaying, starting, or stopping them). Hormones are transported by blood to all the cells in the body, but they only affect very specific target cells, which have specific receptors for that hormone. The hormone causes changes inside those cells.

Glands release only small quantities of hormones, and once the hormone has carried out its function, it is eliminated from the body.

The hypothalamus, a gland located in the brain, connects the nervous system and the endocrine system. It is one of the most important glands because it controls many... Continue reading "Human Endocrine System: Glands, Hormones and Disorders" »

Vineyard Soil

The soil supports the root structure of the vine and influences the drainage levels and amount of minerals and nutrients that the vine is exposed to. The ideal soil condition for a vine is a layer of thin topsoil and subsoil that sufficiently retains water but also has good drainage so that the roots do not become overly saturated. The ability of the soil to retain heat and/or reflect it back up to the vine is also an important consideration that affects the ripening of the grapes.

Annual Cycle of a Vineyard

The annual cycle of a vineyard includes pruning, cutting, trellising maintenance, anchoring, budburst, ploughing down, de-budding, suckering, flowering, first trimming, first leaf thinning, green harvesting, 2 leaf thinning,... Continue reading "Vineyard Soil and Its Importance for Grapevine Growth" »

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

When a cell is not in a state of division and is in the phase known as interphase, its nucleus is more or less spherical and located in the center or near the periphery. During the interphase, we can distinguish the following structures:

• Nuclear membrane: This is a covering formed by two membranes covered in ribosomes. The membranes have perforations called nuclear pores, which allow substances to be exchanged between the nucleus and the cytoplasm.
• Nucleoplasm: This is the liquid in the nucleus.
• Nucleolus: This is a rounded structure that is darker than the rest of the nucleus. It is where the components of the ribosomes are created.
• Chromatin: This is made up of DNA filaments and proteins. During cell division, it condenses and forms chromosomes.

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" »