B16 Reproduction Flashcards
How many parents in sexual reproduction?
2
How many parents in asexual reproduction?
1
How do cells divide in sexual reproduction?
Meiosis
How do cells divide in asexual reproduction?
Mitosis
Offspring from sexual reproduction
Non identical
Genetically different to parents
Offspring from asexual reproduction
Genetically identical to parents
(CLONES)
Advantages of sexual reproduction
Produces variation
Offspring can adapt to environmental changes by natural selection
Advantages of asexual reproduction
Only 1 parent needed
Time and energy efficient
Faster
Successful traits passed on
Disadvantages of sexual reproduction
Slower
Finding a mate is more time consuming
Disadvantages of asexual reproduction
Reduced genetic variation
May have a survival disadvantage if environment changes
Harmful mutations would be passed on
What is meiosis?
Cell division that produces 4 daughter cells, each with a single set of chromosomes
How many daughter cells are produced from meiosis?
4
Gamete
Specialised sex cell formed by meiosis
Chromosome
Long molecule found in the nucleus of cells made from DNA
Gene
Part of a chromosome that codes for a specific protein
Allele
Different forms of the same gene
e.g AA and aa
Dominant allele
Allele only needs one copy to be expressed
Recessive allele
Allele needs two copies to be expressed
Homozygous
When an individual caries two copies of the same allele for a trait
Heterozygous
When an individual carries two different alleles for the same trait
Genotype
Combination if alleles an individual has
Phenotype
Physical expression of the genotype - the characteristic shown
What is the genome of an organism?
The entire genetic material of that organism
What forms DNA?
DNA is a polymer made from 4 different nucleotides
What is a nucleotide made from?
A phosphate
A sugar
Base A, C, G or T
Name the complementary DNA base strands?
C = G
T = A
How many bases are needed to code for one particular amino acid?
3
What are the 2 stages of protein synthesis?
Translation
Transcription
Transcription Protein Synthesis
The DNA code for a protein
remains in the nucleus
, during transcription but a copy, called mRNA, moves from the nucleus to the
ribosome where proteins are synthesized
Translation Protein Synthesis
The mRNA leaves the nucleus and goes to the ribosomes.
Polydactyly
Condition where one has extra fingers or toes
Dominant allele
Cystic fibrosis
Disorder of cell membranes
Recessive allele
Where in the cells are proteins made?
Ribosomes
How many chromosomes do normal human body cells have?
46
Female sex chromosomes
XX
Male sex chromosomes
XY