The absence of centrioles from higher plant cells means that during somatic cell nuclear division there is :

no apparent organiser of mitotic spindles

The absence of centrioles from higher plant cells means that during somatic cell nuclear division there is :}

no apparent organiser of mitotic spindles

no equatorial arrangement of chromo-somes at metaphase.

no new cell wall laid down at telophase.

The absence of centrioles from higher plant cells

Notes on Meiosis

Concepts Used:

Meiosis

Meiosis is a process in which a single cell, a diploid cell, undergoes division twice to produce four haploid daughter cells, and the cells produced are known as the sex cells or gametes (sperms in males and egg in females). It contains half of the original amount of genetic information. The haploids only have half the number of chromosomes of the parent cell.

Features of Meiosis:

It results in the formation of four daughter cells in each cycle of cell division.
The daughter cells are identical to the mother cell in shape and size but different in chromosome number.
The daughter cells are haploid.
Recombination and segregation take place in meiosis.
The process occurs in the reproductive organs and results in the formation of gametes.
The process is divided into two types-Meiosis-I reduces the chromosome number to half and is known as reductional division. Meiosis-II is just like the mitotic division.

Phases of Meiosis

Meiosis can be divided into nine stages. The process is usually divided into two parts. The first time a cell divides (meiosis I) and the second time it divides (meiosis II). The phases are as follows –

Meiosis 1 Stages

The different stages of meiosis 1 can be explained by the following phases :

Prophase 1
Metaphase 1
Anaphase 1
Telophase 1

Meiosis 2 Stages