Yr 11 biology sac work

What are eukaryotes?

Cells of animals, plants, and fungi that contain membrane-bound organelles.

What are prokaryotes?

Bacterial cells that lack membrane-bound organelles.

What distinguishes eukaryotes from prokaryotes?

Eukaryotes have a defined nucleus; prokaryotes have no true nucleus.

How do eukaryotes reproduce?

Through mitosis and meiosis.

How do prokaryotes reproduce?

Through binary fission.

What are chromosomes?

Long strands of DNA.

What segments of DNA code for proteins?

Genes.

Where are chromosomes found in a cell?

In the nucleus.

What is the locus of a gene?

The position of a gene on a chromosome.

What are histones?

Proteins around which DNA is wrapped.

What are nucleosomes?

Structures formed by 8 histones with DNA wrapped around them.

What are exons?

Gene coding regions.

What are introns?

Non-coding regions of DNA.

What is a chromatid?

A strand of DNA.

What is the function of a centromere?

It holds sister chromatids together and attaches spindle fibers during mitosis.

What are telomeres?

Repetitive regions at the ends of chromosomes.

What is a karyotype?

A map of an individual's set of chromosomes to identify chromosomal abnormalities.

How many pairs of chromosomes do humans have?

23 pairs, including 22 pairs of autosomes and 1 pair of sex chromosomes.

What is a diploid cell?

A cell containing two complete sets of chromosomes.

What is a haploid cell?

A cell containing one complete set of chromosomes.

What are the phases of the cell cycle?

G1, S, G2, followed by mitosis.

What happens during prophase in mitosis?

Chromatin condenses into visible chromosomes.

What occurs during metaphase?

Chromosomes align along the metaphase plate.

What happens during anaphase?

Sister chromatids are pulled towards opposite poles of the cell.

What is cytokinesis?

The final step of the cell cycle where the cell divides to form two daughter cells.

What is the difference between homologous chromosomes and sister chromatids?

Homologous chromosomes are the same size and shape but have different genetic information, while sister chromatids are identical copies of a chromosome.

What is the definition of genetic variation?

The diversity present in the DNA of a population.

How is genetic variation advantageous?

It allows populations to adapt to changing environments.

What is non-disjunction?

The failure of chromosomes or sister chromatids to separate properly during cell division.

What is the law of dominance?

In a cross between pure parents for contrasting traits, only one form of the trait appears in the next generation.

What is a monohybrid cross?

A genetic cross between individuals differing in one trait.

What is a pedigree?

A family tree that tracks the inheritance of specific traits.

What is asexual reproduction?

Reproduction that involves only one parent and produces genetically identical offspring.

What are the advantages of sexual reproduction?

Increases genetic variation and adaptability to the environment.

What is cloning?

The process of producing genetically identical organisms.

What is ecological competition?

When species compete for finite resources, which can be intraspecific or interspecific.

What are producers in an ecosystem?

Organisms that produce complex organic compounds from simple inorganic molecules.

What is a keystone species?

A species that plays a crucial role in its ecosystem, disproportionate to its abundance.

What is natural selection?

The process where biological traits become more or less common due to reproductive success.

What is sympatric speciation?

The formation of new species in the same geographic area due to reproductive isolation.