Final Exam Notes - Genetic Variability & Development | Môn Biology - Trường Đại học Quốc tế, Đại học Quốc gia Thành phố Hồ Chí Minh

lOMoAR cPSD| 59078336 LECTURE 9
Explain how sexual recombination generates genetic variability
Sexual recombination generates genetic variability through three main mechanisms:
- Independent assortment (phân li độc lập) of chromosomes during meiosis
(giảm phân) chromosomes are randomly distributed to gametes, generating
diverse combinations of maternal and paternal chromosomes.
- Crossing over (trao đổi chéo) : Homologous chromosomes (nhiễm sắc thể
tương đồng) exchange genetic segments in meiosis (prophase I), producing new gene combinations
- Random fertilization (thụ tinh ngẫu nhiên) : the random combination of
sperm and egg further increases genetic diversity.
This variability is essential for evolution, providing the diversity needed for
natural selection, enabling populations to adapt and improving species survival. LECTURE 10
Describe the role of the extracellular matrix in embryonic development
The extracellular matrix (ECM) is critical in embryonic development by
supporting several key processes:
1. Cell Adhesion and Migration : ECM proteins like fibronectin, laminin,
and collagen help cells adhere and guide their migration during essential
stages such as gastrulation and organogenesis.
2. Tissue Morphogenesis : The ECM shapes and organizes tissues by
interacting with cell surface receptors like integrins, which relay signals to
regulate cell positioning, differentiation, and organization.
3. Growth Factor Regulation : The ECM stores, releases, and modulates
signaling molecules, influencing processes like cell proliferation,
differentiation, and survival.
These roles collectively ensure the formation and functional organization of tissues and organs during development LECTURE 11
Describe the function of erythrocytes, leukocytes, platelets, fibrin
Erythrocytes (Red Blood Cells): lOMoAR cPSD| 59078336
● Primary function: Transport oxygen and carbon dioxide, supporting gas
exchange and cellular respiration.
Leukocytes (White Blood Cells):
● Primary function: Provide defense and immunity. They protect the body against
infections, foreign invaders, and abnormal cells. Platelets:
● Primary function: Facilitate blood clotting by forming a “platelet plug” at injury
sites and initiating the clotting process. Fibrin:
● Role in blood clotting: Forms a fibrin mesh to stabilize the platelet plug,
preventing blood loss and aiding healing.
Explain how the antagonistic hormones insulin and glucagon regulate carbohydrate
Insulin and glucagon are antagonistic hormones that regulate blood glucose levels
through the following mechanisms: Insulin Glucagon
- Secreted by the beta cells of the pancreas
- Secreted by the alpha cells of the pancreas
when blood glucose levels are high.
when blood glucose levels are low. - Functions: - Functions:
+ Promotes glucose uptake by body cells.
+ Stimulates the liver to convert glycogen into
+ Stimulates the liver to store glucose as glucose. glycogen.
+ Encourages the breakdown of fat and protein
+ Slows the breakdown of glycogen into into glucose. glucose.
- Effect: Raises blood glucose levels.
- Effect: Lowers blood glucose levels.
Together, insulin and glucagon maintain glucose homeostasis by ensuring that blood
sugar levels remain stable despite fluctuations in dietary intake and energy expenditure lOMoAR cPSD| 59078336 LECTURE 12
Explain how the hypothalamus and the pituitary glands interact and how they coordinate
the endocrine system in female Hypothalamus:
● Produces and releases GnRH (Gonadotropin-Releasing Hormone) in pulses. Anterior Pituitary:
● In response to GnRH, it secretes FSH (Follicle-Stimulating Hormone) and
LH (Luteinizing Hormone) .
FSH and LH Functions:
● FSH: Stimulates follicular growth in the ovary and estradiol production during the follicular phase.
● LH: Triggers ovulation and supports the formation of the corpus luteum, which
secretes progesterone to prepare the uterus for implantation. Feedback Mechanisms:
● Positive Feedback: High levels of estradiol before ovulation increase GnRH, leading to an LH surge.
● Negative Feedback: Progesterone and estradiol inhibit GnRH, FSH, and LH
after ovulation to regulate the cycle
Functions of Hormones Released by Ovary and Testis
Hormones Released by the Ovary:
1. Estrogen (Estradiol):
○ Promotes development of female secondary sexual characteristics.
○ Regulates ovarian and uterine cycles by promoting endometrium growth and maintenance. 2. Progesterone:
○ Prepares and maintains the uterine lining for pregnancy.
○ Inhibits further ovulation during pregnancy. 3. Inhibin:
○ Suppresses FSH to prevent the development of additional follicles.
Hormones Released by the Testis: 1. Testosterone: lOMoAR cPSD| 59078336
○ Promotes male secondary sexual characteristics (increased muscle mass, deepening voice).
○ Supports spermatogenesis and libido. 2. Inhibin:
○ Inhibits FSH secretion to regulate sperm production.
These hormones play essential roles in sexual differentiation, reproduction, and
secondary sexual characteristic development LECTURE 9 + 12
Compare the growth of a plant in darkness (etiolation) to the characteristics of greening (de-etiolation)
-In darkness, plants undergo etiolation, characterized by long, weak stems, small
yellowish leaves, and lack of chlorophyll. This helps them grow rapidly to reach light.
In light, de-etiolation (greening) occurs, where plants develop short, sturdy stems,
expanded green leaves, and chlorophyll production increases for photosynthesis.
This transformation allows plants to adapt from growing in darkness to thriving in light conditions. LECTURE 14
Distinguish between conservation biology and restoration biology
Conservation Biology: This field aims to preserve life by integrating various
disciplines, including ecology, physiology, molecular biology, genetics, and
evolutionary biology. Its primary focus is on protecting biodiversity and preventing the degradation of ecosystems.
Restoration Biology (referred to as Restoration Ecology in the document): This
field applies ecological principles to return degraded ecosystems to conditions that are
as similar as possible to their natural state