B2 - Cell division 1️⃣✅ Flashcards
What is a undifferentiated cell?
Cells or tissues that do not have specialised/ mature structures or functions
What is gene?
A small packet of information that controls a characteristic of your body
What is a chromosome?
Chromosomes carry the genes that contain the instructions for making new cells
How many chromosomes do you have in your body?
46 chromosomes and 23 pairs
What is a differentiated cell?
A cell that has been specialised to preform a specific function
What is a stem cell?
A undifferentiated cell that can differentiate into one or more specialised cell types
What are adult stem cells?
Stems cells from adults that can differentiate inro certain specialised cells
Where are adult stem cells found?
Bone marrow
What are embryotic stem cells?
Stem cells found in embryos that can differentiate into any type of specialised cell
Where are embryonic stem cells found?
Early human embryos
What is therapeutic cloning?
It is using cells from an adult to produce a cloned early embryo of themselves
Give one advantage to using therapeutic cloning
Stem cells from the embryo are not rejected when transplanted because they are the same genes as the patient
Give one advantage to using adult stem cells
Few ethical issues because it is obtained from adults who consent to their use
Give a disadvantages to using adult stem cells
They can only differentiate into certain specialised cells so cant treat as many diseases
Give 2 advantages to using embryonic stem cells
They can differentiate into any type of specialised cell so can treat all diseases and are easy to obtain as they are found in spare embryos in fertility clinics
Give 2 disadvantages to using embryonic stem cells
There are ethical issues as every embryo is a possible human life and they can transmit viral infections
What are plant meristems?
An area where rapid cell division occurs in root tips and shoot tips
In what part of a root tip does DNA replication take place?
The root cap
In what part of a root tip does mitosis take place?
The zone of cell division
In what part of a root tip does elongation take place?
The zone of elongation
In what part of a root tip does differentiation take place?
The zone of maturation
Give 2 advantages of using plant meristems to clone plants
Rare plant species can be cloned to preserve them as a species and plants with special qualities such as immunity to disease can be cloned to produce many copies
Give 1 disadvantage of using plant meristems to clone plants
There is no genetic variation so one disease could wipe out an entire crop
What is cell division by mitosis?
When body cells divide to form 2 identical daughter cells
What is the purpose of mitosis?
Growth and repair of cells - asexual reproduction
What is the 1st stage of the cell cycle?
Interphase
What happens during the 1st stage of the cell cycle?
Cells grow bigger, chromosomes duplicate and the number of sub-cellular structures increases (mitochondria & ribosomes)
What is the second stage of the cell cycle?
Mitosis
What happens during the second stage of the cell cycle?
During mitosis one set of chromosomes are pulled to either side of the nucleus and the nucleus divides
What is the 3rd stage of the cell cycle?
Cytokinesis
What happens during the 3rd stage of the cell cycle?
The cell cytoplasm and cell membrane divide, forming 2 identical daughter cells
What is a daughter cell?
Genetically identical cells formed when a cell undergoes division by mitosis
Where on a root/shoot would DNA replication take place?
The root/shoot cap
Where on a root/shoot would cell division take place?
The zone of cell division
Where on a root/shoot would elongation take place?
The zone of elongation
Where on root/shoot would differentiation take place?
The zone of maturation
