Cell Division, Genetics, and DNA: Key Concepts
Key Concepts in Cell Division
– Structure that holds two chromatids together is:
b) Centromere
– In multicellular organisms, mitosis results in:
b) Growth and repair of tissues
Each of the two duplicated strands of a chromosome is called a:
a) Chromatid
What is the role of the spindle during mitosis?
a) The spindle fibers help to push and pull the chromosomes to separate them.
All of the following are problems that are faced by a cell that is growing too large, EXCEPT:
d) Too much oxygen entering the cell.
Read MoreHormones, Nervous System, and Brain Functions
Hormonal Regulation of Blood Glucose
Insulin: Released when blood glucose levels are high.
Glucagon: Released when blood glucose levels are low, stimulating the liver to release glucose, thus increasing blood glucose levels.
Antidiuretic Hormone (ADH)
Function: Inhibits urine production by promoting water reabsorption by the kidneys. In large amounts, it causes vasoconstriction of arterioles, leading to increased blood pressure.
Production: Produced by the hypothalamus.
Female Reproductive Hormones
Estrogens:
Read MorePlant Secretory Structures: Types, Mechanisms, and Functions
Plant Secretory Structures
Secretory Structures: These structures are involved in plant metabolism and plant-environment interactions. They are based on the type of shock and the type of secretion secreted. Functions include:
- Production of compounds (cellulose, callose)
- Disposal of surplus (glands eliminate excess salt or water)
- Accumulation of substances (mineral salts in the form of crystals)
- Attraction of pollinators (nectar)
- Protection against herbivorous animals (defensive hairs)
Secreted Substances:
Read MoreBody Defenses, Health, and Illness: Prevention & Treatment
Body Defenses Against Illness
External Defenses: Non-specific reactions to all microorganisms. There are three types:
Physical Defenses
Separate the body’s interior from the environment. Skin covers the outside, and mucous membranes line digestive, respiratory, and reproductive cavities.
Chemical Defenses
Pathogen-blocking secretions.
Biological Defenses
Bacterial flora on skin and mucous membranes produce natural antibiotics, protecting against other pathogens.
Internal Defenses
Activated when pathogens
Read MoreEvolutionary Theory: Natural and Sexual Selection
Evolutionary Theory and Evolutionary Psychology
Darwin
Darwin proposed the first evolutionary theory to explain how change might take place over time, especially how seemingly purposeful or functional structures might have arisen.
Adaptation
Improbably usefulness (too precisely functional to have arisen by chance only).
Williams proposed the following criteria for invoking adaptation:
- Reliability: Does the mechanism regularly develop in most or all members of the species across normal environments and
Renal Function and Urine Formation: Key Physiological Processes
Daily Water Losses
- Insensible water loss: Respiratory evaporation and diffusion into the skin.
- Sweat (exercise and temperature).
- Feces.
- Extracellular urine (60%).
- Intracellular (40%).
Renal Function
Excretion of metabolic waste products, foreign chemicals, drugs, and metabolites of the water balance and hormones. Regulation of electrolyte balance. To maintain homeostasis, excretion of water and electrolytes is essential.
Regulation of Arterial Pressure (Long Term)
By regulating excretion of varying amounts
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