Biology Exam Instructions (2024)

Abscissic acid functions as a growth inhibitor in plants, particularly during stress responses.

The operator is a segment of DNA where repressor proteins bind to inhibit transcription of the genes.

The corpus luteum degenerates into a structure called corpus albicans.

<p>Using unsterilized needles can lead to the transmission of diseases, such as AIDS.</p> Signup and view all the answers

<p>Geitonogamy involves transfer of pollen within the same plant, leading to genetically similar offspring.</p> Signup and view all the answers

<p>The main steps are capping, splicing, and polyadenylation.</p> Signup and view all the answers

<p>Reproductive isolation is the inability of different species to interbreed. Examples include temporal isolation (different mating seasons) and behavioral isolation (different courtship rituals).</p> Signup and view all the answers

<p>Acquired immunity is characterized by specificity and memory, allowing for a stronger response upon re-exposure to the same pathogen.</p> Signup and view all the answers

<p>Estrogen regulates female reproductive functions and promotes the development of secondary sexual characteristics, while progesterone prepares the uterus for potential pregnancy.</p> Signup and view all the answers

<p>Limitations include its inability to account for water movement in tall trees and its insufficient role in transpiration.</p> Signup and view all the answers

<p>Vestigial organs are remnants of organs or structures that had a function in an early ancestor but are now nearly or entirely useless in the current organism.</p> Signup and view all the answers

<p>ZIFT stands for Zygote Intrafallopian Transfer.</p> Signup and view all the answers

<p>The thymus gland is prominent at birth but gradually atrophies in adulthood.</p> Signup and view all the answers

<p>IAA stands for Indole-3-Acetic Acid.</p> Signup and view all the answers

<p>Chloromycetin is derived from the microorganism <em>Streptomyces venezuelae</em>.</p> Signup and view all the answers

<p>Beta cells produce insulin in the islets of Langerhans.</p> Signup and view all the answers

<p>Two meiotic divisions are required to form 300 seeds in angiosperms.</p> Signup and view all the answers

<p>Emigration is the process of individuals leaving one location to settle in another.</p> Signup and view all the answers

A hormone that inhibits plant growth, like abscisic acid, is responsible for regulating plant responses to environmental stress.

The lac operon is a group of genes that control lactose metabolism in bacteria. The 'inducer' is a molecule that triggers the expression of these genes, not a component of the operon itself.

When fertilization doesn't occur, the corpus luteum, a structure in the ovary, deteriorates into the corpus albicans. This is a normal process.

The nasal cavity is divided by the mesethmoid cartilage, which is a specialized type of cartilage.

Using an unsterilized needle can transmit various infectious diseases, including HIV/AIDS, which can potentially lead to fatal consequences.

A stable, mature ecosystem where species composition is relatively constant and no further significant changes occur. It represents the final stage of ecological succession.

Ecological succession that begins in a barren environment, like bare rock or sand, where no previous life existed. Pioneer species colonize the area, gradually creating soil and paving the way for other species.

The first organisms to colonize a barren environment during primary succession. They are hardy and can tolerate harsh conditions, like extreme temperatures or lack of nutrients.

An intermediate stage in ecological succession, characterized by specific plant and animal communities that gradually change over time. These communities show gradual development towards the climax community.

The maximum potential birth rate of a population in ideal conditions, where resources are unlimited and all individuals are capable of reproduction.

Body parts that have lost their original function through evolution. They are reduced in size and may appear rudimentary. These organs provide evidence of evolutionary history.

Zygote Intrafallopian Transfer. A fertility treatment where a fertilized egg (zygote) is transferred into the fallopian tube of a woman. This technique provides a more natural environment for the implanted embryo.

The movement of genetic material (genes) between populations. It can occur through migration, interbreeding, or the transfer of gametes. Gene flow helps to maintain genetic diversity and prevent populations from becoming too isolated.

The process of converting hn-RNA (heterogeneous nuclear RNA) into mRNA (messenger RNA) involves several steps: 1. Capping: A modified guanine nucleotide is added to the 5' end for stability. 2. Splicing: Non-coding introns are removed, and coding exons are joined together. 3. Polyadenylation: A tail of adenine nucleotides is added to the 3' end, also for stability. This mature mRNA is ready to leave the nucleus and participate in protein synthesis.

Reproductive isolation prevents different species from interbreeding and producing fertile offspring. It can occur before mating (pre-mating isolation) or after mating (post-mating isolation).

Acquired immunity is specific, adaptive, and has memory. It develops after exposure to a pathogen and involves specialized cells like lymphocytes (T and B cells).

Ethylene is a plant hormone that promotes fruit ripening, leaf senescence, and abscission (leaf fall). It also influences stem elongation and flower opening.

The lac operon in bacteria is a set of genes responsible for metabolizing lactose. It is an inducible operon, meaning it's only activated when lactose is present. Lactose acts as an inducer, binding to a repressor protein and removing it from the operator site, allowing transcription.