DNA, Cell Division, and Evolution Notes

These flashcards cover key concepts related to DNA, cell division, genetics, and natural selection as presented in the lecture notes.

The genetic information in a cell is organised as follows: Cell → Nucleus → __ → Gene → DNA.

Chromosome

DNA (Deoxyribonucleic Acid) carries the __ for life.

instructions

Humans have __ chromosomes (23 pairs).

46

DNA is a __ helix made up of nucleotides.

double

Base pairing rules: Adenine (A) pairs with __, and Cytosine (C) pairs with Guanine (G).

Thymine (T)

Somatic cells divide by __.

mitosis

Gametes are produced by __.

meiosis

Mitosis has __ phases: Prophase, Metaphase, Anaphase, Telophase + Cytokinesis.

four

Meiosis produces __ gametes (sperm/egg) for sexual reproduction.

haploid

Mitosis results in cells while meiosis results in cells.

2; 4

A gene is a section of __ coding for a trait.

DNA

A __ is the different forms of a gene.

allele

A dominant trait is expressed even if only __ allele is present.

one

The physical traits of an organism are referred to as its __.

phenotype

Homozygous means having two identical __.

alleles

Diploid cells have __ sets of chromosomes.

two

Natural selection leads to __ changes in species over time.

evolutionary

Selection pressure includes environmental factors that influence __.

survival

The process of natural selection includes variation, survival advantage, and __.

reproduction

Fossils provide evidence of __ relationships.

evolutionary

Homologous structures are similar structures in __ species.

different