Chapter 9,10,11 Flashcards
Sexual reproduction
Reproduction that involves two parental sources for the offspring
Gametes
Sex cells
Stimultaneous hemahprodism
When both sperm producing and egg producing organs are present in one cell. Eg earthworm
Sequential hermaphrodism
When an organism starts as one gender and can transfer to the other sex through the right conditions eg coral fish
Chromosomes
A thread like structure composed of DNA and protien
Diploid number
Cell contains full number of chromosomes, one complete set of chromosomes from each parent
Haploid number
Cell contains half the number of chromosomes.
Homologous
Members of matching chromosomes
Reduction division
When a cell starts with 46 chromosomes and gives rise to gametes either egg or sperm that only have 23 chromosomes
Meiosis
The process of cell division that results in production of new cells, each being happily and genetically unique
Cross over
Occurs in meiosis in metaphase 1. Involves exchanging parts of one chromosome with another
External fertilisation
When animals release their gametes into the external environment. They produce very large amount of gametes but there is a lot of wastage. Eg frogs
Internal fertilisation
When fertilisation occurs inside the body of females. The chance of gametes meeting is higher.
Actanim for mitosis
I pick my arse today
Prophase
Chromosomes condense and become visible
Spindle fibres emerge
Nucleolus breaks down
Metaphase
Chromosomes line up along the metaphase plate
Each sister chromatid pair up and attach to spindles of fiber
Anaphase
Chromosomes are pulled apart at the centromere towards opposite poles
Telephase
Nuclear membrane begins to appear
Chromosomes begin to become long and thin
Interphase 3 stages
Gap 1- cell grows, produces protein for DNA replication, Mitrocondria divides
Synthesis stage- replicates DNA (mutation can arise)
Gap 2 - further growth
How does cancer happen
The result of mutations to the genes that regulate the cell cycle
Cancer treatment
Prevent DNA replication or inhibit spindle information
What is the longest stage of the cell cycle
Interphase
Mitosis
Cell division that results in new cells that are genetically identical to original cell
What stage can genetic accident occur when a cell has an extra chromosome
Anaphase as during the splitting of the chromosome one stayed in tact
How many nuclear divisions are in meiosis
2
Pattern for binary fission
2, 4,8,16,32,64
Average time for cell cycle in mammals and binary fission in the right conditions
Cell cycle- 24 hours
Binary fission- 20 minutes
Why do cells divide
Repair damaged cells, replace dieing cells and to grow
What is the purpose of the check points in interphase
To ensure that the daughter cells are formed with little to no problems
What is nondisjunction
When a pair of chromosomes fail to disjoin or separate in anaphase. This results in one cell having an extra chromosome and one having less
Chisma
The point where chromosomes cross over and exchange genetic material. This happens in metaphase 1 of meiosis
What is budding
Common in sponges. When a bud breaks away from the main organism and carried by current to other locations and develop into sponges.
What is parthenogenesis and example of animal
Reproduction without fertilisation. Produced by mitosis and is identical to female parent. Is seen in amphibians
What is spore formation
Common in fungi an example is bread mould. Also common in ferns
What is binary fission
Can only happen in bacteria cells when they split into two
What is an enucleated cell
Egg cells that’s had it genetic material removed (nucleus)
Steps of somatic cell nuclear transfer
- Remove the somatic cell from male mammal.
- Remove nucleus from female mammal
- fuse somatic cell and enucleated egg cell using electro fusion.
- place into the female make for growth of embryo
- place into surrogate mother for further growth
What is vegetative propagation and examples
Asexual reproduction in plants
Eg runners, cuttings, tubers, bulbs
What is the inner cell mass of a blastocyts
It will form the tissues of the embryo
Define blastocyts
A hollow structure in early embryonic development that contains a cluster of cells known as the inner mass
