Docsity
Docsity

Prepare for your exams
Prepare for your exams

Study with the several resources on Docsity


Earn points to download
Earn points to download

Earn points by helping other students or get them with a premium plan


Guidelines and tips
Guidelines and tips

IAL EDEXCEL BIOLOGY UNIT 2 QUESTIONS, Exams of Biology

IAL EDEXCEL BIOLOGY UNIT 2 QUESTIONS

Typology: Exams

2023/2024

Available from 11/07/2024

ROCKY-B
ROCKY-B 🇰🇪

5

(5)

5.9K documents

Partial preview of the text

Download IAL EDEXCEL BIOLOGY UNIT 2 QUESTIONS and more Exams Biology in PDF only on Docsity!

IAL EDEXCEL BIOLOGY: UNIT 2

Explain what is many by polygenic inheritance? (2 marks) - Answers- Describe and Explain two adaptations of the human egg cell (4 marks) - Answers- - lipid droplets are present which suppiles energy for division.

  • half set of chromomes so that a full number of chromosomes are restored at fertilisation. Explain what is meant by the term totipotent stem cell. (2 marks) - Answers- totipotent stem cells are undifferentiated stem cell that can form into all cell types even placenta cells like the embryonic cells. Explain the function and structure of the plant cell wall (3 marks) - Answers- - gives plant cell its uniform shape
  • gives strength and support
  • composed of polysaccharide cellulose Explain the function and structure of chloroplast in the plant cell (3 marks) - Answers- - site of respiration
  • contains a green pigment called chlorophyll, which has its own DNA and large inner membrane, which all increase the surface area for light absorption.
  • not all plant cells contain chloroplasts Explain the function and structure of amyloplast in the plant cell (3 marks) - Answers- - colorless structure
  • stores starch as a form of amylopectin
  • which is used to provide energy in respiration when required
  • they are found in large areas of starch storage, like potato tubers Explain the function and structure of vacuole in the plant cell (3 marks) - Answers- - a permanent structure which regulates the osomotic balance of the cytoplasm
  • keeps the plant cell turgid and provides support
  • can also stores enzymes, proteins and poisons Explain the function and structure of tonoplast in a plant cell (1 marks) - Answers- - a structure that has a membrane that contains solution that dissolves various substances Explain the function and structure of plasmodesmata in a plant cell (2 marks) - Answers- - cytoplasmic connections that allow substances from one cell to pass more easily into a neighbouring cell. Explain the function and structure of pits in a plant cell (3 marks) - Answers- - regions in the cell wall that are very thin
  • arranged in pairs
  • one pit from one cell is lined up with the pit in the adjacent cell. Explain the function and structure of the middle lamella in a plant cell (3 marks) - Answers- - layer found within cell walls of neighbouring cells
  • made up of pectin that acts like a glue
  • it bind cellulose to either side of the cell wall