DNA and Genetics Flashcards
reproduction
- asexual reproduction (no mate, clones of parent)
- sexual reproduction (fusion of male and female gametes (sex cells)
gametes
produced through meiosis
process of gamete fusion
creates the zygote (first cell of offspring) then develops to the embryo and foetus
male reproductive system
- testis - male gonads contain sperm storage in the epididymis, location of testosterone synthesis
- scrotum - sac containing the testes
- vas deferens - sperm duct, connects to the urethra
- cowper’s gland, seminal vessel and prostate gland add fluid to sperm, forming semen
gonads
glands that produce reproductive hormones
female reproductive system
- ovary - female gonads, location of ova storage
- fallopian tube - (oviducts) connect each ovary to the uterus
- uterus - the womb, muscular organ lined with endometrium
- vagina - muscular canal with opening, cervix
traits
the physical characteristics and behaviors of an organism (inherited or learnt)
genes
segments of DNA that code for traits
- can be turned off and on per environmental factors
- contains instructions for constructing parts of proteins
homozygous
two of the same, homozygous dominant/recessive
hetrozygous
a copy of each allele
genotype and phenotype
the pair of alleles
the physical expression of the genotype
DNA
- a chemical found in the nucleus of most cells
- deoxyribonucleic acid
- contains segments of genes
- polymer composed of 2 strands of nucleotides
4 nitrogen bases of nucleotides
- adenine
- cytosine
- guanine
- thymine
(cytosine + guanine, adenine + thymine)
genome
all of the dna in an organism
dna no.s in humans
DNA is coiled into 23 pairs of chromosomes total of 46
- 22 pairs somatic
- 1 pair sex chromosomes
homologous chromosomes
result of sexual reproduction, 2 copies of the same chromosome
diploid organisms
contain 2 copies of each chromosome
forms of proteins
- enzymes - act as biological catalysts
- hormones - chemical messengers
- transport - carries oxygen to cells and carbon dioxide away
- structural - form tissues
- contractile - allow movement through muscle contraction
- motor - produce mechanical movement
- antibodies - proteins that play an important role in the immune system
amino acids
small organic molecules that are the components of proteins
codon/triplet
three nucleotides in a row
- given instructions as to which amino acid to code for
- 1 start codon and 3 stop codons in an amino acid
cell cycle
DNA is replicated into 2 daughter cells
why do cells reproduce?
- growth and repair
cells need to be replace due to damage or age and in growth. (creating new cells in somatic cells is mitosis) - reproduction
cell replication to create gametes via meiosis
2 main types of cells in the human body
- gametes - sex cells
- somatic cells - no sex cells :)
steps of mitosis
- membrane of nucleus breaks down to condense chromosomes
- chromosomes lined up down the middle of the cell (made up of two parts called chromatids)
- sister chromatids pulled apart to each pole of the cell
- cytokinesis - the cell divides
